Investments - Schedule of Investment Funds (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Alternative Investment [Line Items]
Investment funds, Unfunded Commitments	$ 433,000
Unfunded commitments, including past investment period	$ 57,500
Minimum
Alternative Investment [Line Items]
Expected life of non-redeemable funds	7 years
Extension options term of non-redeemable funds	1 year
Expected life of redeemable funds	6 months
Maximum
Alternative Investment [Line Items]
Expected life of non-redeemable funds	10 years
Expected life of non-redeemable funds	12 years
Extension options term of non-redeemable funds	4 years
Expected life of redeemable funds	36 months
Commercial mortgage loans
Alternative Investment [Line Items]
Investment funds, Fair Value	$ 566,142	$ 411,315
Investment funds, Unfunded Commitments	189,725
Opportunistic and private credit
Alternative Investment [Line Items]
Investment funds, Fair Value	202,008	181,410
Investment funds, Unfunded Commitments	191,192
Infrastructure
Alternative Investment [Line Items]
Investment funds, Fair Value	179,627	165,887
Investment funds, Unfunded Commitments	0
Other
Alternative Investment [Line Items]
Investment funds, Fair Value	38,989	36,971
Investment funds, Unfunded Commitments	52,479
Investment funds
Alternative Investment [Line Items]
Investment funds, Fair Value	986,766	$ 795,583
Investment funds, Unfunded Commitments	433,396
Unfunded commitments, including past investment period	$ 645,000